Support symbol literals.

tests/compiler/dart2js_extra/private_symbol_literal_test.dart

Index: tests/compiler/dart2js_extra/private_symbol_literal_test.dart
diff --git a/tests/compiler/dart2js_extra/private_symbol_literal_test.dart b/tests/compiler/dart2js_extra/private_symbol_literal_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..31a278310e2901733b38735616af91a1005f9244
--- /dev/null
+++ b/tests/compiler/dart2js_extra/private_symbol_literal_test.dart
@@ -0,0 +1,22 @@
+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Test symbol literals with underscores.
+// These are currently unsupported by dart2js.
+
+library symbol_literal_test;
+
+main() {
+  print(#a);
+  print(#_a); /// 01: compile-time error
+
+  print(#a.b);
+  print(#_a.b); /// 02: compile-time error
+  print(#a._b); /// 03: compile-time error
+
+  print(#a.b.c);
+  print(#_a.b.c); /// 04: compile-time error
+  print(#a._b.c); /// 05: compile-time error
+  print(#a.b._c); /// 06: compile-time error
+}